Authentication: project details

This document is not a step by step tutorial. If you want a step by step tutorial, you can refer to the Hello World project. The objective of this tutorial is to explain how to use TriggeredMethodContext and file resources.

Overview

In this project, there are mainly 2 elements:

• An Authentication component
• A console application

Authentication component

The Authentication component loads a list of users (login and password) from a xml file. It receives requests to check if login/password couple is valid or not.

When the component starts, the OnComponentInitialized() method of the class TriggeredMethodContext is called by the XComponent runtime. On this method, you can initialize your component. On this project, we load a file which is stored as a resource of the component.

Note: To add a file resource in XComponent, you can use the following screen:

XComponent provides a useful Api to load files resources of a component. This Api is: ComponentManager.Resources.

The code below is the implementation of the OnComponentInitialized method:

        public void OnComponentInitialized()
        {
            XmlDocument xmlDocument = new XmlDocument();
            xmlDocument.LoadXml(componentManager.Resources.GetResourceAllText("users.xml"));

            XmlNodeList usersList = xmlDocument.SelectNodes("//user");
            List<User> users = new List<User>();
            foreach (XmlNode userNode in usersList)
            {
                User user = new User();
                user.Name = userNode.SelectSingleNode("name").InnerXml;
                user.Password = userNode.SelectSingleNode("password").InnerXml;
                users.Add(user);
            }

            Users = users;
        }

The TriggeredMethodContext class can be used to store data shared by several state machines. Indeed, TriggeredMethodContext is a singleton.

Note: When you decide to store some data in the TriggeredMethodContext, you should managed concurrency by yourself.

You can easily extend ICustomTriggeredMethodContext interface by adding your own properties. In this project, we have extended the interface this way:

    public partial interface ICustomTriggeredMethodContext : ITriggeredMethodContext
    {
        IEnumerable<User> Users { get; }
    }

The implementation of the ICustomTriggeredMethodContext is the TriggeredMethodContext class.

Once you have added your own properties on the TriggeredMethodContext, you can easily call them from any triggered method.

    //Pseudo code
    var value = TriggeredMethodContext.Instance.MyProperty;

Authentication state machine

The authentication state machine contains the entry point of the component. On the Initializing state we check if the list of user is not empty. If the list is not empty, the state machine goes to the Up state.

LoginStatus state machine

This state machine receives login/password requests. If the login/password couple is valid, the state machine goes to state LoginSucess otherwise the state machine goes to state LoginError.

Authentication Console Application

The console application sends 2 events: the first one to test login failure and the second one to test login success.

			 using(var myauthenticationserviceApi = new ApiWrapper<authenticationserviceApi>())
			 {
				ClientApiOptions clientApiOptions = new ClientApiOptions(); 
 
				if(myauthenticationserviceApi.Init(myauthenticationserviceApi.Api.DefaultXcApiFileName, clientApiOptions))
				{

                    var entryPoint = myauthenticationserviceApi.Api.Authentication_Component.GetEntryPoint();
				    if (entryPoint.StateCode == (int)Authentication_StateMachine.AuthenticationStateEnum.Up)
				    {
                        string requestId1 = Guid.NewGuid().ToString();
                        string requestId2 = Guid.NewGuid().ToString();
				        using (AutoResetEvent resetEvent = new AutoResetEvent(false))
				        {
                            myauthenticationserviceApi.Api.Authentication_Component.LoginStatus_StateMachine.LoginError_State.InstanceUpdated +=
                              delegate (LoginStatusInstance instance)
                              {
                                  if (instance.PublicMember.RequestId == requestId1 ||
                                      instance.PublicMember.RequestId == requestId2)
                                  {
                                      Console.WriteLine("Authentication failed");
                                      resetEvent.Set();
                                  }
                              };

                            myauthenticationserviceApi.Api.Authentication_Component.LoginStatus_StateMachine.LoginSuccess_State.InstanceUpdated +=
                               delegate (LoginStatusInstance instance)
                               {
                                   if (instance.PublicMember.RequestId == requestId1 ||
                                       instance.PublicMember.RequestId == requestId2)
                                   {
                                       Console.WriteLine("Authentication succeeded");
                                       resetEvent.Set();
                                   }
                               };

                            var checkLogin = new CheckLogin()
                            {
                                RequestId = requestId1,
                                Login = "Luke.Skywalker",
                                Password = "noforce"
                            };
                            Console.WriteLine("Authenticate as {0} with password: {1}", checkLogin.Login, checkLogin.Password);
                            myauthenticationserviceApi.Api.Authentication_Component.Authentication_StateMachine.SendEvent(entryPoint.Context, checkLogin);
                            resetEvent.WaitOne();

                            checkLogin = new CheckLogin()
                            {
                                RequestId = requestId1,
                                Login = "Luke.Skywalker",
                                Password = "force"
                            };

                            Console.WriteLine("Authenticate as {0} with password: {1}", checkLogin.Login, checkLogin.Password);
                            myauthenticationserviceApi.Api.Authentication_Component.Authentication_StateMachine.SendEvent(entryPoint.Context, checkLogin);

                            resetEvent.WaitOne();
                        }
                    }
				    else
				    {
				        Console.WriteLine("Authentication service is not up.");
				    }



                }
				else			
				{
					AnalyseReport(myauthenticationserviceApi.Report);
				}
			}

Note: You may notice the usage of AutoResetEvent. Because, all events are received asynchronously in XComponent, you should use this kind of Api the main thread with the messages thread of the XComponent’s Api.

• Run your console application. You should end up with the following output:

Questions?

If you have any questions about this sample, please create a Github issue for us!